A motorcycle tyre has a tread band including a central portion and two shoulder portions arranged at axially opposite sides of the central portion. The central portion includes a first plurality of grooves extended according to a substantially longitudinal direction and alternatively arranged at opposite sides of the equatorial plane of the tyre. Each groove of the first plurality of grooves has a substantially curvilinear course such as to form a concavity. The central portion further includes a sub-portion substantially free of grooves placed astride the equatorial plane of the tyre. Each of the shoulder portions includes a second plurality of grooves arranged obliquely relative to the equatorial plane of the tyre.

A tire 1 according to an example of an embodiment includes a plurality of lands, and a tread having a sipe formed in at least part of the lands. An inclined surface is formed between an opening end on at least one side in a width direction of the sipe and a ground contact surface, the inclined surface having a linear shape in cross section and continuing from the ground contact surface. An intermediate surface is formed between the inclined surface and the sipe, the intermediate surface having an inclination angle with respect to the ground contact surface of 0 degrees or having an inclination angle with respect to the ground contact surface that is smaller than an inclination angle of the inclined surface with respect to the ground contact surface.

A tire has a tread portion including a first land portion including first and second circumferential edges and and a tread surface. On the first land portion, curved grooves are provided in a tire circumferential direction. Each curved groove extends from a first end on the first circumferential edge side, terminates at a second end within the first land portion, and includes first and second curved portions and on the first end and second end sides, respectively. The first curved portion is an arc curve with a radius of curvature having a center on the first circumferential edge side of the curved groove. The second curved portion is an arc curve with a radius of curvature having a center on the second circumferential edge side of the curved groove.

A tyre includes a tread portion having a tread surface being provided with a plurality of lateral grooves extending in a tyre axial direction. In a cross-sectional view perpendicular to a longitudinal direction of the at least one of the plurality of lateral grooves, the at least one of the plurality of lateral grooves includes a pair of groove walls and a groove bottom. At least one of the pair of groove walls includes a serrated portion including first surfaces and second surfaces that are arranged alternately. Each first surface is inclined outwardly in a groove width direction toward the groove bottom and has a radially inner end thereof, and each second surface extends substantially parallel with the tread surface from the radially inner end of a respective one of the first surfaces toward a groove centerline of the at least one of the plurality of lateral grooves.

A ground contact region of the tread portion of a studdable tire includes a center region located over a range corresponding to a length of 5 to 25% of a ground contact width from a tire centerline on each of both sides of the tire centerline in a tire width direction; and two shoulder regions located on both sides of the center region in the tire width direction. In each of the center region and the shoulder regions, a plurality of the stud pin installation holes are disposed along each of four or more pin arrangement lines extending in a tire circumferential direction. An average value of adjacent intervals between the pin arrangement lines in the center region is larger than an average value of adjacent intervals between the pin arrangement lines in each of the shoulder regions.

Present invention provides a tread for a tire being provided with a plurality of grooves extending in an orientation having a non-zero angle A with circumferential orientation, at least two circumferentially adjacent grooves delimiting a contact element, the contact element having at least one incision extending in an orientation substantially parallel to the grooves, the contact element being delimited into sub-contact elements, on a plane perpendicular to the orientation in which the plurality of grooves being extending and to the contact face, each sub-contact elements having a length Ls between the plurality of grooves and the at least one incision or between two incisions, an outermost portion of each the sub-contact element having a radius Rs smaller than a radius Rt of an outline OL of the tread at an intersection between the outline OL and the outermost portion, the radius Rs of the outermost portion of the sub-contact elements is smaller than or equal to 16.0 mm and greater than or equal to 5.0 mm.

A motorcycle tyre (1) is described comprising an equatorial plane (X-X) and a tread band (8) comprising a radially inner portion (13) and a radially outer portion (11) respectively comprising a first and a second vulcanized elastomeric material obtained by vulcanizing respective elastomeric materials comprising 100 phr of at least one elastomeric diene polymer, from 30 to 130 phr of at least one reinforcing filler comprising an amount greater than 75% or, respectively, equal to or greater than 80% of a white filler. In the tyre (1) the ratio R1 between the dynamic elastic modulus (E′) and the tandelta measured at a frequency of 10 Hz and at 70° C. of the first vulcanized elastomeric material is comprised between 27 and 35, whereas the ratio R2 between the dynamic elastic modulus (E′) and the tandelta measured at a frequency of 10 Hz and at 70° C. of the second vulcanized elastomeric material is comprised between 15 and 30, the ratio R1/R2 being greater than or equal to 1.1.

A walking mechanism for driving a machine body includes a walking wheel group having a plurality of walking wheels attached to the machine body, with two front and two rear wheels relative to a traveling direction. The machine body has two sides with a pair of one of the front wheels and a one of the rear wheels being respectively located on each of the sides and driven to rotate synchronously. Each walking wheel includes an auto tire casing with a tread outer side having a tread pattern distributed along a circumferential direction of the auto tire casing. The tread pattern is configured as a plurality of tread ribs with a respective tread groove formed between each adjacent pair of the tread ribs, the tread pattern radiating outward from an axial center of the walking wheel. A related robot and self-walking mower are also disclosed.

A tire comprises a directional tread which forms a contact patch AC during running. The tread comprises a plurality of blocks (21A, 21B) which form a contact surface SC. The surface voids ratio is defined by TES=(AC−SC)/AC. The blocks (21A, 21B) are organized into patterns (26) of blocks of pitch P which succeed one another in the circumferential direction (X), in a pattern comprising at least one sipe. The sipes density is defined by the formula

[00001]$\mathrm{SD}=\frac{{.Math.}_{i=1}^n\mathrm{lpyi}}{P*W}*1000,$

where n is the number of sipes, lpyi is the projected distance of the sipe i in the axial direction (Y), and W is the width of the tread. Simultaneously, SD is at least equal to 10 mm-1 and at most equal to 70 mm-1, and TES is at least equal to 0.40 and at most equal to 0.70.

A first and a second tread pattern portions P1 and P2 on each side of a tire equator (Co) are line symmetry except being circumferentially misaligned, and are each provided with oblique lateral grooves 3, inner and outer joint grooves 4 and 5 connecting between the circumferentially adjacent oblique lateral grooves 3, inner terminating grooves 7 disposed between the inner and outer joint grooves 4 and 5, outer terminating grooves 8 disposed between the outer joint grooves and a ground contact edge (TE), and center joint grooves 6 alternately connecting the oblique lateral grooves of the first and second tread pattern portions. The inner and outer joint grooves 4 and 5 and the inner and outer terminating grooves 7 and 8 are inclined to different directions from the oblique lateral grooves 3. The outer terminating grooves 8 extend on extended lines of the outer joint grooves 5.